Electrical heater.



P. E. GARLSON.

ELEGTRIUAL HEATER. APPLICATION FILED 1111.11.25, 1914.

Patented Feb. 23, 1915.

A TTORNE Y.

OFFICE.

FREDERICK E. CAR'LSON, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO LANDERS,

FRARY & CLARKK, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CON- ELECTRICAL HEATER.

Specification of Letters Patent.

Patented Feb. 23, 1915.

Application filed March 25, 1914. Serial No. 827,099.

SON, a citizen of the United States, and a resident of New Britain, in the county of Hartford, State of Connecticut, have invented certain new and useful Improvements in Electrical Heaters, of which the following is a specification.

This invention relates particularly to a new and useful construction of electrical heaters adapted for use with various cooking utensils, hot pads, etc.

One use to which the invention may be put is illustrated in my co-pending application, S. No. 783,475, filed August 7, 1913, the substance of the present application representing in part matter divided out of the earlier application.

Referring to the drawings Figure 1 is a plan View of one form of heater with a part" of the cover broken away to show construction. Fig. 2 is a central vertical section through said heater. Fig. 3 is a view of a modified form of electrical unit.

In the form shown in Figs. 1 and 2 the heater comprises a rectangular or other suitably shaped wire frame a about which are wound the edges 1) of lateral flanges 0 extending from the sides of a shallow recessed base 03. e is a cover plate which rests upon and is secured to the flanges c of the base (Z. These flanges 0 have apertures f formed in them and the resistance coil is located within the recessed base, consequently any drip that there might be from food which is being cooked would drop onto the cover 6 and be carried off onto the flanges and down through the apertures The interior of the heater is thus protected from the accumulations of dirt, grease, etc., and the possi-' bility of short-circuiting the resistance coil is avoided. If the heater is to be used above the food which is to be cooked, as in the case of broiling, it is turned upside down, and in place of the cover e a wire netting may be used, the base of the heater reflecting the heat down onto the food.

Arranged about the edges of the recess in the base are metal strips 2 folded over a packing of electrical insulation 3, as asbestos, and the .tops of these strips are notched at intervals as indicated at 4. Alternately short and long arms, 5, 6, have their ends embedded in this insulating material where it is exposed by the notches 4, and have loops at their ends which support the resistance coils m, y. These coils are stretched slightly as they are seated in the loops and then the loops are pinched to hold them under tension.

Centrally arranged within the heater is an annular band 10 which acts as a spacer between the top and bottom of the heater,

and also as a diffuser of heat, and the top.

and bottom plates are slightly recessed as at 11 so as to position it. These depressions in the base and cover of the heater are also useful in determining the direction of movement of these plates as they expand whenv heated, and prevent the snappin of the metal and the consequent jarring 0 an oven for instance which would otherwise be occasioned if the plates were fiat and free to buckle in either direction. Such jarring of an oven interferes with the successful cooking or baking of various foods. In the bottom of the'heater apertures 20 are formed to permit of the circulation of air through and around the resistance coils.

One end of the coil m is connected with the plug 30. The corresponding end of the coil y is connected with the plug 31; and the opposite ends of both coils are connected with the plug The connection of these plugs may be controlled in any suitable manner and permit of securing three dilferent heats, first, by connecting the coils in series; next, by cutting out one coil; and next, by connecting the coils up in parallel.

In the modification shown in Fig. 3, which is a type of unit especially adapted for heating pads and other similar purposes, the heater is circular rather than square and comprises what in this case may be a continuous metal strip 2 folded about asbestos or other insulation 3 and notched at intervals as indicated at 4 which permits of embedding the short and long arms 5 6 in the insulation, the ends of the arms having T- shaped or other properly formed heads 7 so as to prevent them from being pulled out. Here but a, single resistance coil is shown connected-with the plugs 12, 13, and threadtrical unit which will be referred to in the claims is intended to refer to the resistance coil and its immediate supporting parts.

I claim as my invention:

1. An electrical unit comprising electrical insulating material, a metallic sheath "folded thereabout and notched at intervals, arms embedded at one end in said insulating material, a resistance coil supported at the other ends of said arms, and terminal plugs to which said coil is connected.

2. An electrical unit comprising electrical insulating material, a metallic sheath folded thereabout and notched at intervals, alternately long and short arms embedded at one end in said insulating material, a resistance coil supported at the other ends of said arms, and terminal plugs to which said coil is connected.

3. An electrical heater comprising a casing and an electrical unit located Within said casing and supported thereby, said unit comprising an electrical non-conducting material, arms supported thereby, a resistance coil supported by the ends of said arms, and terminal plugs to which the ends of said coil are attached. i p

4. A- heater comprising a shallow recessed base, strips of electrical insulation covered by a metallic sheathing located within said recessed base against the side walls thereof,

the upper edge of the metallic sheathingbeing notched at intervals, arms embedded in said insulating material where it is exposed through said notches, with their ends bent to form inwardly extending lateral supports, and an electrical resistance coil secured to said supports.

5. A heater comprising a base, strips of electrical insulating material arranged about the sides of said base, arms embedded in said insulating material and having their ends bent to form inwardly projecting supports, some of which are of greater length than others, a pair of electrical resistance coils, one of Which is mounted on the longer supports and the other on the shorter supports, and contact plugs projecting from one edge of said base and with which said coils are connected.

6. An electrical unit comprising an annulus of electrical insulating material, a metallic sheath folded thereabout and notched at intervals, radially disposed, alternately long and short arms embedded in said 7 insulating material at one end, a coiled electrical resistance supported at the inner ends of said arms, and attachment plugs to which the ends of said coil are connected.

FREDERICK E. CARLSON.

Witnesses:

L. L. REDICK, F. G, RUSSELL. 

